nixos-logwatch

This flake provides a NixOS module for logwatch.

It probably does not cover all use cases, as it has been lifted out of my personal configuration. Any suggestions or PR are welcome!

The master branch of this repository packages tagged logwatch releases (currently 7.11), while the unstable branch will be updated more regularly following the logwatch master branch.

Basic usage

In your flake.nix: add this flake to your inputs:

inputs = {
  ...
  nixos-logwatch = {
    url = "github:SFrijters/nixos-logwatch";
    inputs.nixpkgs.follows = "nixpkgs";  # It's probably best to follow your existing nixpkgs
  };
};

and add nixos-logwatch.nixosModules.logwatch to your modules.

In your configuration.nix:

services.logwatch = {
  enable = true;
  range = "since 24 hours ago for those hours";
  journalCtlEntries = [
    { name = "sshd"; }
    { name = "postfix"; output = "short"; }
    { name = "sudo"; unit = "session*"; }
  ];
};

Available options:

• enable: Whether to enable the service.
• mailto: Recipient of the reports.
• range: Time range to digest (use logwatch --range Help for details).
• detail: Detail level of the analysis.
• service: Which services to digest.
• startAt: When to run.
• journalCtlEntries: What to watch (see below).

Advanced usage

The option services.logwatch.journalCtlEntries contains attribute sets with the following name-value-pairs:

• name: The name of the journalctl service that is watched.
• title (optional): The title of the section in the report.
• output (optional): Forwarded to the --output flag of journalctl. Defaults to cat.
• unit (optional): Forwarded to the --unit flake of journalctl. Defaults to ${name}.service.
• script (optional): If the service does not have a script available in the logwatch package, you can provide your own here.

Example:

logwatch-nix-gc-script = pkgs.writeShellApplication {
  name = "logwatch-nix-gc";
  text = ''
    cat - | grep -i "store paths deleted"
  '';
};

services.logwatch.journalCtlEntries = [
  {
    name = "nix-gc";
    title = "Nix garbage collection";
    script = "${lib.getExe logwatch-nix-gc-script}";
  }
  ...
];

Some useful / example scripts are provided as packages in this flake.